Orthodontic appliances to position the teeth of patients are designed to contact the teeth of a patient and apply forces to those teeth that will cause the teeth to move toward an arrangement that the orthodontist determines to be ideal or to otherwise satisfy a treatment objective. Goals of orthodontic treatment include moving the teeth of a patient as closely as possible to the finish tooth positions determined ideal for achieving the desired treatment result, minimizing the time during which the patient must wear the appliances used for the treatment, and minimizing the time of the orthodontic practitioners, or chair-time, in treating the patients. All of these goals are served by reducing the amount of manual adjustment of the appliances, such as wire bending, needed by the orthodontic practitioner, during the course of the treatment of a patient with an appliance.
A most common and useful type of orthodontic appliance includes a set of brackets bonded to each of the respective teeth of a patient that support and are interconnected by a resilient archwire. The archwire is elastically deformed from its unstressed shape and applies forces to the teeth through the brackets as the wire tends to return to its unstressed shape. The trend in appliance design or selection is to employ an archwire having a predetermined shape that, when mounted on brackets secured to the teeth at predetermined design positions, will urge those teeth toward desired treatment positions without, or with minimal, intervention by the orthodontist in bending the wire. Standard appliances that are designed to anatomical averages typically require some adjustment during the course of a patient's treatment. Custom appliances ideally eliminate or minimize this need for adjustment. For the goals of minimal or no archwire adjustment to be met, however, brackets must be accurately placed on the patient's teeth at exact positions for which the appliance was designed.
For accurate placement of orthodontic brackets onto the teeth of a patient, the use of custom placement jigs has been proposed. Such jigs have been described, for example, in U.S. Pat. No. 5,368,478 and International Patent Application No. PCT/US00/35558, hereby incorporated herein by reference, to place brackets of orthodontic appliances. Such jigs may include a precision formed custom surface that is manufactured from tooth crown-shape data that has been scanned from the patient's teeth. Each such surface is intended to precisely fit over the crown of a patient's respective tooth and to hold a bracket of an orthodontic appliance against its proper design position on the tooth while the bracket is being bonded to the tooth surface.
While the provision of such jigs has gone far to serve the orthodontic objectives discussed above, there remains a need to improve the function and handling of such jigs to better serve these orthodontic objectives.